Another thing that I think could alter the landscape, and make for some really interesting possibilities, is adjusting the Aura strength. I had a thread bout treating the Aura as a magnitude, where each level is a +5 instead of +1 for Magic Realms.
It's located here.
It makes magic auras really powerful, and even a +3 Aura makes spell casting and learning, and even item creation much easier. It makes divine auras absolutely horrid. Since the typical town will take a -45 (Aura 35/magnitude3 triple strength of Divine aura) to your casting total. But maybe that's not so bad. It's yet another reason why magi avoid cities, if at all possible. Those magi that are living in the city, are either extremely powerful, have a lacuna for their covenant, are getting something for the effort, or some combination of the three. It makes the Divine Aura 1 something to be wary of, too. Item creation isn't something to be afraid of when you change the availability of vis, though.
An interesting side effect is that magi can actually develop really powerful spells and cast them, when in a magic aura. Outside of that aura, they might not be able to cast the spell, or doing so might leave them fatigued. I think having a wide grimoire of spells available to a magus is important, regardless of the saga's overall power level. If you tamp down hard on books to increase Arts, this is an alternative method of getting them access to spells, they wouldn't get access to without a higher TeFo combination, while at the same time drastically limiting the locations where such spells can be cast, or changing the cost of casting spells in the field/on adventure in the "real" world from nothing to fatiguing.